Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Trading carats for nanometers - and defective diamonds for crystal clear microscopy

26.02.2009
Large, perfect diamonds are precious to almost all of us but to some scientists, it is the defects that really matter. This is because defects can form nanoscopic color centers, which play a key role in the development of both quantum computing and quantum cryptography.

A research team at the Max Planck Institute for Biophysical Chemistry in Göttingen has now probed these color centers inside the crystal with unprecedented resolution using an optical microscope. Using STED microscopy, the scientists identified even densely packed color centers and determined their position inside the crystal with a precision better than 0.15 nanometers, corresponding to the dimension of an atom.


Sharp focus: Recordings of lattice defects in diamond crystals are 28 times sharper with the super resolving STED microscope than with conventional fluorescence microscopy methods, namely 8 nanometers. Picture: Rittweger & Hell, MPIbpc

Diamonds are brilliant not only as gem stones but scientists are also increasingly interested in these precious crystals. As the perfect jewel, the colorless variant glitters brilliantly - but in science it is the much cheaper fluorescent diamonds that cause the sensation. Their color comes from impurities, such as nitrogen atoms, in the diamond lattice.

If a nitrogen atom sits next to a vacancy in the crystal lattice, a luminescent defect of atomic size is formed. Electrons of these color centers can - similar to dye molecules - be excited by laser light. When they return to the ground state, the excitation energy is converted to fluorescence light. This fluorescence glowing and their ability to form atomically small magnets render color centers in diamond extremely interesting.

Researchers hope to use diamond color centers as small processors in quantum computing to speed up specific arithmetic operations, and their suitability for encoding highly sensitive data is currently being explored. However, there is a crucial drawback for observing these color centers inside the crystal: single defects can only be recognized with a fluorescence microscope, but only if they are further apart than approximately 200 nanometers (millionth of a millimeter) because this is the resolution limit of a standard optical microscope.

Stefan Hell's group at the Max Planck Institute for Biophysical Chemistry in Göttingen succeeded in recording the first images of densely packed individual color centers employing STED (Stimulated emission depletion) microscopy. They pushed the current resolution limit of STED down to a few nanometers. Diamond color centers closer than a tiny fraction of the resolution limit could be separated and their position determined with a precision of 0.15 nanometers. Scientists have now a method at hand to individually address densely packed color centers - with conventional lenses and focused light. For the ongoing research and application of these color centers this is a major breakthrough. This work is also important for the field of crystallography, which now has another method at hand to study crystal structures locally.

That nitrogen-vacancies fluoresce after excitation with laser pulses also makes them attractive for a different research field: biological fluorescence nanoscopy. Scientists plan to reveal a live cell's secrets using fluorescent diamonds, requiring tiny diamond nano particles which can be used for labeling cells."Organic fluorescent dyes, which we routinely use for STED, have the disadvantage that they blink and eventually bleach", says Eva Rittweger, a PhD student in the department. "However, color centers in diamonds are extremely photostable even when observed for hours in the STED microscope."

Research groups in Würzburg, Stuttgart, as well as in Asia and America are working on applying the nanocrystals to biological and medical fundamental research. "If we are successful in exploiting this property in nanodiamonds, one would have a new class of fluorescent markers and a form of fluorescence nanoscopy without bleaching. This could, in combination with the nanometric resolution of STED microscopy, improve imaging of the cell at the nanoscale", says Stefan Hell.

Original publication:
Eva Rittweger, Kyu Young Han, Scott E. Irvine, Christian Eggeling, and Stefan W. Hell. STED microscopy reveals crystal colour centres wit nanometric resolution. Nature Photonics, Online Publication, February 25, 2009 | doi:10.1038/nphoton.2009.2
Contact:
Prof. Dr. Stefan W. Hell, Department of NanoBiophotonics
Max Planck Institute for Biophysical Chemistry, Göttingen
Phone: +49 551 201 -2500, -2503
E-Mail: shell@gwdg.de
Dr. Carmen Rotte, Press and public relations office
Max Planck Institute for Biophysical Chemistry, Göttingen
Phone: +49 551 201 -1304
E-Mail: crotte@gwdg.de

Dr. Carmen Rotte | Max-Planck-Institut
Further information:
http://www.mpibpc.mpg.de/groups/pr/PR/2009/09_06_en/
http://www.mpibpc.mpg.de/groups/hell/

More articles from Life Sciences:

nachricht Nesting aids make agricultural fields attractive for bees
20.07.2017 | Julius-Maximilians-Universität Würzburg

nachricht The Kitchen Sponge – Breeding Ground for Germs
20.07.2017 | Hochschule Furtwangen

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

Leipzig HTP-Forum discusses "hydrothermal processes" as a key technology for a biobased economy

12.07.2017 | Event News

 
Latest News

Researchers create new technique for manipulating polarization of terahertz radiation

20.07.2017 | Information Technology

High-tech sensing illuminates concrete stress testing

20.07.2017 | Materials Sciences

First direct observation and measurement of ultra-fast moving vortices in superconductors

20.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>